Adults have a dark, conspicuous eye line extending from the nostril to the shoulder. Basic coloration varies, with background color green, brown, gray, reddish, or bronze. Dark spots and stripes are often visible on the head, back, and legs. Most have a dark Y or triangular spot on the head between the eyes. Adult body length is 0.75 to 2 inches. Eggs and Tadpoles: Eggs are laid in small clusters of 10 to 70. The tadpoles are brown/bronze with eyes located on the sides of the head.

Diagnostic Characteristics

This is the only frog in Montana with a combination of obvious toe pads and an eye stripe ending at the shoulder.

(Observations spanning multiple months or years are excluded from time charts)

Habitat

Pacific Chorus Frogs are regularly found in the water only during the breeding period in spring. They announce their presence during this time by calling frequently at night and sporadically throughout the day. Following breeding, they move into adjacent uplands and are rarely seen. In western Montana they breed in temporary ponds in lower elevation forests and intermountain valleys shortly after snowmelt. Eggs hatch in 2 to 3 weeks and tadpoles take 8 to 10 weeks to metamorphose. Use shallow, quiet waters for breeding. Move along ground or in low shrubs at night. Take shelter during day in dense vegetation, under rocks/logs, in rodent burrows, etc. (Nussbaum et al. 1983).

Ecological Systems Associated with this Species

Details on Creation and Suggested Uses and Limitations

How Associations Were Made
We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:

Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;

Examining the observation records for each species in the state-wide point observation database associated with each ecological system;

Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".

Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if point observations were associated with that system.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.

Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: http://mtnhp.org/requests/default.asp) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.

Maxell, B.A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.

Northern ID: males arrive in breeding ponds early to mid-April; females mid- to late April. Eggs layed April to mid-May; hatch early to mid-May. Metamorphose mid-Jul to mid-September. Prefer warmer, more open ponds, but observed calling in water 2 C, air 0.5 C (Schaub and Larsen 1978).

Claussen, D.L. 1971. A comparative study of the thermal and water relations of the tailed frog, Ascaphus truei and the Pacific treefrog, Hyla regilla. Ph.D. Dissertation. University of Montana, Missoula, MT. 103 p.

Cope, E.D. 1875. Check-list of North American Batrachia and Reptilia; with a systematic list of the higher groups, and an essay on geographical distribution. Based on the specimens contained in the U.S. National Museum. U.S. Natioanl Museum Bulletin 1: 1-104.

Maxell, B. A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to USFS Region 1, Order Number 43-0343-0-0224. University of Montana, Wildlife Biology Program. Missoula, MT. 161 p.

Maxell, B.A. 2002a. Amphibian and aquatic reptile inventories in watersheds in the South and Middle Forks of the Flathead River drainage that contain lakes being considered for application of piscicides and subsequent stocking of west slope cutthroat trout. Report to the Region 1 Office of the U.S. Forest Service and the Montana Department of Fish, Wildlife, and Parks. Montana Cooperative Wildlife Research Unit and Wildlife Biology Program, University of Montana, Missoula, MT. 62 pp.

Citation for data on this website:Pacific Treefrog — Pseudacris regilla. Montana Field Guide. Montana Natural Heritage Program and Montana Fish, Wildlife and Parks. Retrieved on December 13, 2017, from http://FieldGuide.mt.gov/speciesDetail.aspx?elcode=AAABC05100